Crystallinity Measurements of Unstabilized and HALS-stabilized LDPE Films Exposed to Natural Weathering by FT-IR, DSC and WAXS Analyses

Abstract The crystallinity of unstabilized low-density polyethylene (LDPE) films and those stabilized with hindered-amine light stabilizers (HALS) was studied under natural weathering conditions, up to 170 and 650 days, respectively. The HALS tested was Tinuvin 783, added to the polymer in the concentration of 0.6% (wt/wt). The crystallinity changes were evaluated by means of Fourier-Transform Infrared (FT-IR) spectroscopy, wide-angle. X-ray scattering (WAXS), and Differential scanning calorimetry (DSC). The comparison of the results obtained by FTIR and WAXS confirmed the accuracy of using the rocking bands 730 and 722cm−1. The trends of the crystallinity measured by DSC were different from those determined by FT-IR and WAXS.